StreamBlade

StreamBlade addresses the unique challenges of multiple program streams. It is a 1 RU BLADE unit for streaming applications that features key Wheatstone AoIP, audio processing and codec bandwidth optimization technology.

• Selectable AAC, Opus, and MP3 encoders targeting high to low bit rates for reaching a broad range of end user devices and players.

• Accepts eight input steams of native WheatNet-IP audio directly from a soundcard or AoIP driver as well as RTP sources, each capable of four outputs for a total of 32 total output streams.

• Five-band intelligent AGC, dual-band limiter and other audio processing designed to optimize the performance of encoded audio content.

• Lua transformation filters adapt metadata input from any automation system into any required output format for transmission to the CDN server.

• Local I/O connectivity for other than WheatNet-IP audio network applications.

• Analog and AES67 input for non-WNIP applications.

“Putting all processing and bandwidth optimization functions in one box that talks native IP audio just makes sense for studios today that are managing five, six or more streams,” said Rick Bidlack, Wheatstone systems and lead StreamBlade design engineer.

Unique to StreamBlade is its five-band AGC with RMS density driven time constants for establishing tonal balance and level consistency between incoming music sources. Unlike the conventional approach of applying multiband gain control followed by fast compression to build uniform loudness and density from one music source to the next, this AGC is designed specifically for streaming applications and eliminates aggressive RMS attack times that can interfere with codec performance.

“Fast time constants (compression) can add intermod sidebands around a sustained note or bass note, which the codec has to spend bits on instead of the signals that are actually part of the program. That can be bad for any stream, but it’s especially bad for low bit-rate streams that don’t have a lot of data bits to begin with,” explained Jeff Keith, Senior Product Development Engineer for Wheatstone’s audio processing line.

Also unique to StreamBlade is a two-band final limiter section made for streaming that removes hard limiting or clipping from the processing chain. “Clipping creates harmonics that the encoder wants to throw bits at, and much of that isn’t particularly pleasant to the ear,” added Keith.

Also onboard is a stereo width management section that produces a perceived stereo field yet eliminates the big swings in dynamic L-R that can skew the codec algorithm as well as bass boost and monaural bass features for optimizing the quality of the bit stream.

A selectable six-band parametric equalizer with peak and shelf functions, high and low pass filtering for removing noise or hum, and two-stage phase rotator to correct voice asymmetry are also included in StreamBlade.

StreamBlade can be configured and managed from a laptop and web browser using WheatNet-IP NAVIGATOR software. It has two Ethernet ports, one for direct connectivity into the WheatNet-IP audio network on one end and another for connectivity into a WAN for streaming to a CDN or other service provider.